Portable collapsible scaffold



Sept. 22, "1910 1... ATCHEY 3,5 94 I I PORTABLE COLLAPSIBLE SCAFFOLD IFiled March 10, 1969 2 SheetsSheet 1 m0 m2 ml /0@ 48 /f4a 4 w 52 50 /572 a2 30 ma 'INVE'NTOR. 650,955 La Arc/45y v ATTOFA/E- 5 United StatesPatent 3,529,694 PORTABLE COLLAPSIBLE SCAFFOLD George L. Atchey, 3715Bella Vista, Midwest City, Okla. 73112 Continuation-in-part ofapplication Ser. No. 678,734, Oct. 27, 1967. This application Mar. 10,1969, Ser. No. 805,773

Int. Cl. A01g 19/04; E04g 1/00; E06c /06 US. Cl. 1822 17 Claims ABSTRACTOF THE DISCLOSURE A scaffold apparatus mountable in the bed of a truckand expandible to an elevated status, or similarly expandible whendemounted and rested on the ground. The structure includes a basestructure and a pair of parallel boom elements, each pivotally securedat one end to the base structure and at their opposite ends to a workplatform. The work platform includes a floor, side fences pivotallysecured on opposite ends of the floor, and a plurality of gate members.Each gate member is pivotally secured to one side fence in such a mannerthat it can be pivoted to a position adjacent such fence. Each sidefence can then be pivoted with the adjacent gate members to a positionparallel to the floor of the work platform. A piston and cylinderstructure is interconnected between the base structure and booms forelevating the booms. Transverse members on the base structure slidinglyand rotatingly receive portions of a plurality of outrigger jacks. Thejacks can be rotated to an out-of-the-way position for storage, or to aground contacting position wherein they extend to the outside of a truckcarrying the scaffold apparatus. The jacks can then be used foroff-loading the scaffold from the truck.

CROSS-REFERENCE TO RELATED APPLICATION This application is acontinuation-in-part of copending application Ser. No. 678,734, filedOct. 27, 1967, now US. Pat. No. 3,472,337.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates to expandable work platforms and scaffolding which can be usedto elevate a workman to a high work location, or folded down to acompact, inoperative status. More particularly, the invention relates toa collapsible work platform and outrigger jacks used in expandablescaffolding of the type which can be transported and used while mountedupon a light truck.

Brief description of the prior art A number of instances exist where itis necessary to elevate a workman above ground level in an outdoorlocation for the purpose of permitting the workman to make relativelyrapid repairs to elevated structures, such as street lights, trolleypower lines, traffic signal lamps, and the like. For this purpose, anumber of special vehicles have heretofore been built which incorporatea rather massive scaffolding structure which can be elevated to selectedheights, can be swiveled about so as to move the workman in a horizontaldirection, and can be driven from one location to another. .Many ofthese structures contain complicated machinery and are relativelyexpensive to construct and maintain. In most instances, the scaffoldingor structure employed to elevate the workman cannot be easily detachedor demounted from the framework of the vehicle, but rather, is made apermanent portion of the vehicle, thus rendering the vehicle incapableof other utility, and requiring that both the vehicle and scaffoldingstructure always be present at the same loca- 3,529,694 Patented Sept.22, 1970 tion. In other instances, equipment of the general typedescribed has been so large in its vertical dimension that freedom ofmovement of the vehicle is somewhat restricted, and care must beexercised in traversing underpasses and trunnels having a limitedvertical clearance.

BRIEF DESCRIPTION OF THE PRESENT INVENTION The present inventionprovides a portable collapsible scaffold which can be utilized toelevate a workman to a substantial height, either when the scaffold issupported on the ground, or when it is mounted in quick detachablefashion on a relatively small, lightweight truck. The scaffold can beeasily mounted on, or demounted from, a truck by a single operator, sothat the entire assembly, including the truck and collapsible scaffold,can be operated by a single workman. The portable collapsible scaffoldcarries a self-contained power unit which permits it to be operatedindependently of the power plant of the truck. Moreover, when thescaffolding is folded down wardly to its collapsed or travelingposition, it adds very little to the total height of the truck andconsequently problems of inability to pass beneath relatively lowvertical clearance structures are seldom encountered.

Broadly described, the present invention comprises; a base structure,which is adapted to be detachably secured to the bed of the truck,having a forward end portion and' a rear end portion. A pair oftransverse members are extended generally horizontally across the basestructure and secured to the base structure, each transverse memberpreferably having a bore extending therethrough. A plurality ofoutrigger jacks are provided which detachably engage the respectivetransverse members. Each outrigger jack includes an elongated sleevehaving an upper and a lower end; a ground contacting portion whichadjustably engages the lower end portions of the elongated sleeve,whereby the height of the elongated sleeve is adjustable by raising andlowering the ground contacting portion; and a bar which is secured atone end portion thereof to the uppermost end portion of the elongatedsleeve. The opposite end of the bar is slidingly disposed in the bore ofone of the transverse members. Means is provided to secure each bar inposition with respect to each transverse member. A pair of elongatedboom elements is provided, each of the boom elements being pivotallysecured at one end thereof to the base structure. Means is provided toraise and lower the booms by pivotation about the horizontal axesthereof.

A horizontally extending work platform is provided and includes agenerally rectangularly shaped base frame which is pivotally secured tothe ends of the booms opposite their ends which are pivotally secured tothe base structure. A pair of side guard fences extend, in a firstposition, generally perpendicular to the base frame, and each guardfence is pivotally secured to one side of the base frame in such mannerthat when each side guard fence is pivoted to a second positiongenerally parallel to the base frame, a space exists between each sideguard fence and the base frame. A pair of gate members is disposed abovethe base frame of the platform. Each gate member is pivotally secured toan end of one of the side guard fences so that, in one position, thegate members and guard fences form a rectangular enclosure. One of thegate members on each respective side guard fence can be pivoted to aposition generally adjacent and parallel to the respective side guardfence, and the other of the gate members of the same side guard fencecan be pivoted to a position generally adjacent the gate member securedto the other end of the guard fence. In this position the pair of gatemembers on each guard fence generally occupy the space between each sideguard fence and the base frame when each side guard fence is pivoted toa position generally parallel to said base frame.

From the foregoing general description of the invention, it will havebecome apparent that one object of the invention is to provide animproved, portable, collapsible scaffold which can be easily mounted on,or demounted from, a lightweight truck so that the truck can be utilizedfor servicing and maintaining vertically elevated structures, and canalso be used at other times in the normal fashion characteristic oflightweight trucks without impairment by the presence of thescaffolding.

An additional object of the invention is to provide a vehicle carryingelevatable scaffolding to permit a workman to be elevated to a highvertical level, which scaffolding can be folded down to a compactposition in which the vertical dimension of the entire structure is onlyslightly greater than the distance from the ground to the top of the cabof the vehicle.

A further object of the invention is to provide a portable collapsiblescaffold which includes a self-contained power plant, and which can beused either when mounted on a transporting vehicle or when rested uponthe ground.

A still further object of the invention is to provide a portablecollapsible scaffold structure which can be used with a maximum degreeof safety by a workman who is elevated by the scaffold structure.

An additional object of the invention is to provide a portablecollapsible scaffold which automatically locks in a collapsed, compact,inoperative position.

One other object of the invention is to provide a portable collapsiblescaffold structure which can be quickly and easily disassembled if it isdesired to separately transport various portions of the structure fromone location to the other, or to repair or replace various portions ofthe structure.

Another object of the invention is to provide a work platform for aportable collapsible scaffold structure, which platform can be easilyand quickly placed in an assembled or in a nonoperating position and yetprovides a safe secure working area.

Another object of the invention is to provide a portable scaffoldstructure, including manual jack elements which permit the scaffoldstructure to be loaded and off-loaded on a vehicle for purposes oftransport, with such loading or off-loading being accomplished by asingle person.

Another object of the invention is to provide a portable collapsiblescaffold structure having outrigger jack elements which can be rotatedto an out of the way position when not in use without completelydisassembling the jack elements.

A further object of the invention is to provide a portable collapsiblescaffold structure having outrigger jack elements which are removablysecured to the scaffold structure in such a manner that when the jackelements are in the operating position, any movement of the scaffoldstructure, including the outrigger jacks, tends to more securely tightenthe interconnection between the outrigger jacks and the scaffoldstructure, thereby providing a safer and a more secure structure.

Another object of the invention is to provide a portable collapsiblescaffold structure which is relatively inexpensive in construction, yetis of strong, durable character and possessed of a long and trouble-freeoperating life.

In addition to the foregoing described objects and advantages,additional objects and advantages will become apparent as the followingdetailed description of the invention is read in conjunction with theaccompanying drawings which illustrate the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in elevation of theportable collapsible scaffold of the present invention as the scaffoldappears when mounted on a pickup truck in it elevat d op i status.

FIG. 2 is a view similar to FIG. 1, but showing the scaffold in itstransport or collapsed status and illustrating the outrigger jackspositioned and connected for off-loading the scaffold from the truck.

FIG. 3 is a view similar to FIG. 2, but in elevation from the rear of apickup truck in which the portable collapsible scaffold of the presentinvention is mounted.

FIG. 4 depicts the portable collapsible scaffold of the invention as itappears after it has been off-loaded from the truck and placed upon theground with the scaffold collapsed to a compact, inoperative status.

FIG. 5 is a plan view of the work platform employed in the scaffold. Thegate members of the work platform are shown in dashed lines to betterillustrate the manner in which these gate members are folded to acollapsed inoperative position.

FIG. 6 is a front elevation view of the work platform shown in FIG. 5.The side guard fences and the collapsed gate members are shown in dashedlines to better illustrate the manner in which these guard fences andgate members are folded down to a collapsed, inoperative position.

FIG. 7 is an enlarged partial elevation showing the interconnectionbetween an outrigger jack and the transverse member, which is securedgenerally between forward corner posts forming a portion of theinvention.

FIG. 8 is a view of a section taken substantially along the lines 8--8of FIG. 7. A nonuse position of a securing pin forming a part of theinvention is shown in dashed lines.

BRIEF DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION In thefollowing description, reference will be made to various portions of theaccompanying drawings, with reference numerals associated with leadlines which have arrowheads being utilized to designate broadcombinations which include several subassemblies or several elementshaving a unitary function in the overall operation of the scaffold ofthe invention. Numerals which are connected to various structural partsby plain lead lines (having no arrowheads) will be utilized to designateindividual elements of structure.

Referring initially to FIG. 1 of the drawings, a vehicle, typically apickup truck 10, is shown supporting the portable collapsible scaffoldof the present invention, designated generally by reference numeral 12.It should be understood, however, that one of the inventive aspects ofthe present disclosure is considered to be the structural combination ofthe portable collapsible scaffold with a vehicle of the type depicted,due to the novel and peculiar adaptability of the scaffold to the bedstructure of the typical pickup truck. Thus, the truck 10 includes theusual fiat, substantially horizontally extending bed (not shown) locatedto the rear of the truck cab 14 and having sideboards or side walls 16.A tailgate 20 (see FIG. 3) is usually provided to provide a closure orgate extending across the rear of the bed of the truck 10.

The portable collapsible scaffold 12 includes a base structure 22comprising a pair (only one is shown) of substantially parallel,horizontally spaced, horizontally extending runners 24 (see FIG. 4), andfour substantially parallel, vertically extending corner posts (only twoare shown), with the rear corner posts being designated by referencenumeral 26 and the forward corner posts being designated by referencenumeral 28. The corner posts 26 and 28 are each secured at their lowerends to the runners 24, and the rear corner posts 26 extend to aslightly greater height than the forward corner posts 28 for a reasonhereinafter to be described. A pair or (only one is shown) central,vertically extending posts 30 are also provided in the base structure 22and are secured at their lower ends to the runners 24.

A plurality of transverse frame members interconnect the two runners 24,holding the runners 24 in a horizontal distance apart, and a pluralityof b aces are provided generally between the runners 24 and thetransverse frame members for purposes of reinforcement. An uppertransverse member (not visible in the drawings) interconnects thevertically extending posts 30. A plurality of long diagonal braces 32are extended between the vertical posts 26, 28, and 30 in a mannerdepicted in FIGS. 1, 2, and 4.

As shown in FIG. 3, an upper transverse member 34 extends between andinterconnects the upper end portions of the rear corner posts 26. Asecond upper transverse member 34a (shown in FIGS. 7 and 8) extendsbetween and interconnects the upper end portions of the forward cornerposts 28. In a preferred form, the transverse members 34 and 34a areidentical in construction and each transverse member 34 and 34a has abore 36 extending therethrough, as clearly shown in FIGS. 7 and 8 withrespect to the transverse member 34a. The transverse member 34a isdisposed generally on the upper end of each forward corner post 28, andthe upper end of each forward corner post 28 is secured to therespective end portion of the transverse member 34a, as shown in FIGS. 7and 8.

The transverse member 34, which interconnects the rear corner post 26,extends through an aperture provided in each respective post 26, and issecured to each respective post 26 generally about this aperturedportion. In this position, it is apparent, that the bore 36 through thetransverse member 34 will communicate through each respective end post26.

In a preferred form, the transverse members 34 and 34a will lie insubstantially the same horizontal plane above the runners 24.

A pair of apertures 38 are provided in each respective transverse member34 and 34a. One such aperture 38 in the transverse member 34a is shownin FIG. 8. Each aperture 38, in the respective transverse member 34 or34a, is disposed generally near one of the corner posts 26 or 28, and islocated generally above the horizontal centerline of each respectivetransverse member 34 and 34a.

A second pair of apertures 40 are provided in each respective transversemember 34 and 34a, one such aperture 40 is shown in FIG. 8 with respectto the transverse member 34a. Each aperture 40 is located generallybelow the horizontal centerline of each respective transverse member 34and34a. Each aperture 40 is positioned such that the centerline of eachaperture 40 is aligned with the centerline of each aperture 38respectively. The diameter of each aperture 40 is slightly less than thediameter of each aperture 38, for reasons which will be made apparenthereinafter. A pair of step plates 42 are secured to the inner sides ofthe rear, vertically extending posts 26 at substantially the midportionsthereof.

Mounted upon the base structure 22 of the portable collapsible scaffold12 are a pair of elongated booms, hereinafter ter med an outer boom 44and an inner boom 46. The terms outer and inner are utilized indescribing these booms because of the nested relationship of the boomswhen they are in their collapsed or inoperative positions as hereinafterfurther explained. The outer boom 44 includes a pair of elongated,longitudinal members 48 which are interconnected by transverse anddiagonal brace members 50 and 52, respectively. The outer boom 44 alsoincludes a second pair of elongated longitudinal members (not shown),which are spaced horizontally from the pair of longitudinal members 48shown in FIGS. 1 and 2. A plurality of horizontally extending transversemembers (not shown) extend between the two uppermost longitudinalmembers 48 (only one is shown) of the boom 44 and generally support aladder (not shown). The ladder provides access to a work platform 54,which extends horizontally and interconnects the two upper ends of thebooms 44 and 46 as will be described hereinafter.

As shown more clearly in FIGS. 3 and 4, one end of the boom 44 ispivotally connected to the base structure 22, and specifically to theupper end portions of the rear corner posts 26 by means of a pivot bar56. The pivot bar 56 is journaled in a pair of pillow blocks formed atthe upper end of each of the rear corner posts 26. The pillow blocks areformed, such that the boom 44 can be completely disengaged from theupper portions of the rear corner posts 26.

The boom 46, as shown more clearly in FIG. 1, is constructed generallysimilarly to the boom 44 and thus includes a plurality of longitudinalmembers 58 (only two are shown), transverse braces 60, diagonal braces62, and a plurality of transverse, horizontally extending members, whichextend between the two upper most longitudinal members 58 (only one isshown) of the boom 44. The horizontal spacing between the pairs oflongitudinal members 58 (only one pair is shown) of the boom 46 is lessthan the horizontal spacing between the corresponding longitudinalmembers 48 of the boom 44, so that the boom 46 can fit within, or benested inside of the boom 44 when the two booms are pivoted downwardlyto the position depicted in FIG. 2. It will further be noted that oneend of the boom 46 is connected in a manner hereinafter described to thework platform 54, while the opposite end of this boom is pivotallyconnected to the base structure 22. The connection of the boom 46 to thebase structure 22 is accomplished by the use of a pivot bar 66 to whichthe boom 46 is secured and which extends through a pair of pillow blockssecured to the upper ends of the central posts 30. The pillow blocks areconstructed similarly to the pillow blocks hereinbefore mentioned, andare constructed to permit the boom 46 to be detached from the basestructure 22 and removed from the assembly when desired.

The work platform 54, shown more clearly in FIGS. 5 and 6, includes arectangular base frame 68. The base frame 68 may be provided with a pairof heavy longitudinal boom attaching beams, which are positionedinwardly on the base frame 68 and connected by a pair of transverserods. An expanded metal floor grille 69 is included on the base frame 68and generally supported by the boom attaching beams and the transverserods.

Disposed on the base frame 68 of the work platform 54 is a pair ofside-guard fences 70 and 72. The side guard fences 70 and 72 aredisposed on opposite ends of the work platform 54, respectively, and inan opened or operating position, as shown more clearly in FIGS. 1, S and6, each side guard fence 70' and 72 extends generally perpendicular tothe base frame 68. Each side guard fence 70 and 72 is pivotally securedto the base frame 68 by a pair of triangularly shaped hinge members 74,which extend generally perpendicular from each side guard fence 70 and72. The hinge members 74 are secured on the opposite ends of each sideguard fence 70 and 72, and each hinge member 74 is disposed generallyadjacent the base frame 68. The outer most end portion of each hingemember 74 from the respective side guard fence is pivotally secured to alug 76, which extends perpendicular to the base frame 68 and is securedon one end portion thereof to the base frame 68. It is apparent from theforegoing that each hinge member 74, and therefore each side guard fence70 and 72, will pivot about the interconnection between each hingemember 74 and each lug 76 respectively. It is also apparent that, sincethe interconnection between each hinge member 74 and each lug 76 isoffset from the vertical axis of each side guard fence 70 and 72,respectively, that when each side guard fence 70 and 72 is pivoted in adirection 78 (see FIG. 6) generally toward the base frame 68 to aposition, wherein each sideguard fence 70 and 72 is generally parallelto the base frame 68, a gap will exist between the base frame 68 andeach side guard fence 70 and 72, respectively, for purposes to bedescribed hereinafter.

Each side guard fence 70 and 72, includes a flange portion 80, whichextends along one side thereof and is generally perpendicular to eachside guard fence 70 and 72, respectively. As shown more clearly in FIG.5, each side guard fence 70 and 72 is disposed on the base frame 68,such that the respective flange portions 80 extends from opposite (ornonaligned) ends of each side guard fence 70 and 72, respectively.

A pair of gate members 82 and 84 are pivotally secured to each sideguard fence 70 and 72, respectively, on one side of the base frame 68.Each gate member 82 and 84 includes an upper rectangular portion 86 anda post member 88, which extends from one end portion of the rectangularportion 86 of each gate member 82 and 84, respectively, to a positiongenerally adjacent the base frame 68.

One end of each rectangular portion 86 opposite the post member 88 end,of each gate member 82, is pivotally secured to the flange portion 80 ofeach side guard fence 70 and 72, respectively. Since each flange portion80 extends a distance from each side guard fence 70 and 72 respectively,when each gate member 82 is pivoted in a direction 90 generally towardeach side guard fence 70 and 72, respectively, to a position generallyparallel to each respective side guard fence 70 and 72, it is apparentthat a gap will exist between each gate member 82 and each side guardfence 70 and 72, respectively.

One end of each rectangular portion 86, opposite the post member 88 and,of each gate member 84 is pivotally secured to one end portion, oppositethe flange portion 80 end, of each side guard fence 70 and 72,respectively. It is apparent from the foregoing, that each gate member84 can be pivoted in a direction 92 generally toward each side guardfence 70 and 72, respectively. In a preferred form, the overall verticalheight, from the base frame 68, of each side guard fence 70 and 72 andeach gate member 82 and 84, is substantially the same. The horizontallength, with respect to the base frame 68, of each side guard fence 70and 72 is substantially the same as the respective end of the base frame68. The horizontal length, with respect to the base frame 68, of eachgate member 84 is such that when each gate member 84 is pivoted in adirection 92, to a position adjacent the respective side guard fence 70and 72, the post member 88 end of each gate member 84 will extend aposition near each flange portion 80 of each side guard fence 70 and 72,respectively, but will not contact the flange portion 80. The width ofeach gate member 84 is slightly less than the distance which each flangemember 80 extends from each side guard fence 70 and 72, so that wheneach gate member is pivoted to a position adjacent each side guard fence70 and 72, respectively, each respective flange portion 80 will extendslightly beyond each gate member 84, respectively. In a preferred form,the gate members 82 and 84 are constructed identical with respect toform, so that their relative positions on the work platform 54 may beinterchanged, for purposes of economy in manufacture.

The length of the base frame 68, extending between the side guard fences70 and 72, is slightly greater than the overall horizontal length of oneof the gate members 82 and one of the gate members 84 combined, so that,in an assembled position as shown in FIGS. 1, and 6, each gate member 82and each gate member 84 will extend along the length of the base frame68, generally meeting at the central portion of the base frame.

A retaining plate 94 is secured on each side of the base frame 68 andextends generally perpendicular thereto. Each retaining plate 94 isdisposed to arrest the pivotal movement of each gate member 82 and 84 ina direction opposite the directions 90 and 92, resepectively, byengaging the post member 88 of each respective gate member 70 and 72.

A latching sleeve 96 is pivotally secured to the upper portion of eachgate member 84 by a pin 98. Each latching sleeve 96 has a generallyU-shaped cross section so that when each latching sleeve 96 is pivoteddownwardly, a portion thereof will receive and engage a portion of eachgate member 82 respectively. It is apparent that in this position ofeach latching sleeve 96, as shown in FIGS. 5 and 6, each latching sleeve96 will secure the gate members 82 and 84 in an opened, operativeposition.

Extending downwardly from the under side of the base frame 68 of thework platform 54 are a pair of boom attachment brackets 100 and 102. Itwill be noted in referring to FIG. 1 that each of the boom attachmentbrackets 100 (only one is shown) is pivotally secured through a pin 104to the inside of the upper ends of the outer boom 44. The other boomattachment brackets 102 in each set are secured to the opposite side ofhe base from 68 of the work platform 54, from the boom attachingbrackets 100 and are secured by suitable pivot pins 106 to the outsidesof the upper end of the inside boom 46. It will thus be noted that thestaggered position of the boom connecting brackets 100 and 102 relativeto each other, conjunctively with the smaller transverse dimension ofthe inside boom 46 as compared to the outside boom 44, permit the twobooms to be nested with the inside boom 46 positioned inside the outsideboom 44 when both booms are lowered to a substantially horizontallyextending position as shown in FIGS. 2 and 4. Moreover, the pivotal axesof the pivot pins 104 and 106 extend parallel to each other, and to theaxes of the pivot bars 56 and 66 used to connect the booms 44 and 46 tothe base structure 22 so that a parallelogram type arrangement isprovided in which the base frame 68 of the work platform 54 isconstantly maintained in a horizontal position as the booms 44 and 46are pivoted upwardly. It may also be pointed out here that at such timeas the inner and outer booms 46 and 44, respectively, are pivoteddownwardly to their collapsed, substantially horizontally position asshown in FIGS. 1, 3 and 4, the scaffold structure becomes locked in thisposition and cannot be displaced therefrom by vibration or tilting.Rather, a positive force must be applied on the outer and uppermost ofthe two booms in order to break this positive interlock and allow theparallelogram type motion to occur.

For the purpose of elevating the booms 44 and 46 to raise the workplatform 54 to a desired height, the portable collapsible scaffold 12 ofthe invention includes a self-contained power plant which includes aprime mover, preferably a gasoline engine 108, which is supported on asuitable support plate 110 mounted on the base structure 22 of thescaffold. The support plate 110 also supports a hydraulic pump 112,which is driven by the engine 108 and supplies hydraulic power fluidthrough suitable conduits (not shown) to a main piston and cylinderassembly designated generally by reference numeral 114, and to anauxiliary piston and cylinder assembly, designated generally byreference numeral 116, respectively (see FIG. 1).

The piston and cylinder assembly 114 includes an enlongated cylinder 118which is pivotally anchored to the base structure 22. A piston islocated in the cylinder 118 and has secured thereto an elongated pistonrod 120. The upper end of the piston rod is pivotally secured by a pivotpin 122 to a pair of opposed bracket plates 124 secured to the innerboom 46. The bracket plates 124 also support a transverse cylinder baseplate upon which is mounted a short hydraulic cylinder 126 whichencloses a piston having secured thereto, and extending from thecylinder, a relatively short piston rod 128. The free upper end of thepiston rod 128 bears against one of the cross members of the boom 44when the booms 44 and 46 are in their collapsed, nested relationship asshown in FIGS. 2 and 4, and functions in a manner hereinafter describedfor releasing the positive interlock of the booms which is developedwhen they are in their nested, horizontally extending positions.

A remote control unit 129 is secured to the side guard fence 72 of thework platform 54. The remote control unit 129 is interconnected with thepower plant of the portable scaffold 12, such that the elevating andlowering of the booms 44 and 46 may be controlled by an individualstanding on the work platform 54.

For the purpose of permitting the portable collapsible scaffoldstructure 12 to be off-loaded from the vehicle 10, there are provided aplurality of outrigger jacks designated generally by reference numeral130. Each of i the outrigger jacks includes a ground-contacting plate132 which is secured on the lower end of a threaded shaft 134 whichextends upwardly into an internally threaded sleeve 136. A jack handle138 cooperates with the threaded shaft 134 in such a way that thethreaded shaft 134 may be further extended from the sleeve 136 in orderto lift the base structure 22 of the scaffolding above the bed of thetruck in a manner hereinafter described.

As shown in FIG. 3, a bar 140 is secured to the upper most end of theinternally threaded sleeve 136 and extends generally perpendicularthereto. Each bar 140 is shaped to slidingly fit in the bore 36 of therespective transverse members 34 and 34a. The length of the bar 140 issuch that the outrigger jacks 130 are spaced outwardly from the sides ofthe vehicle 10 during the operation of the outrigger jacks 130, as willbe described in more detail hereinafter.

As shown in FIGS. 7 and 8, with respect to transverse member 34a, eachbar 140 has a bore 142 extending a distance therethrough. An aperture144 is provided in each bar 140 and is located to be generally above thehorizontal centerline of each bar 140. A second aperture 146 is providedin each bar 140 and is located to be generally below the horizontalcenterline of each bar 140. 'Each aperture 146 is in diametric alignmentwith each aperture 144. The diameter of each aperture 146 is slightlyless than the diameter of each aperture 144 and the diameter of eachaperture 144 is slightly less than the diameter of the aperture 38 ineach respective transverse member 34 and 34a. The apertures 144 and 146are provided such that, when the bar 140 is inserted a particulardistance into the bore 36 of the respective transverse member 34 or 34a,the apertures 144 and 146 will be in alignment with the apertures 38 and40 of the respective transverse member 34 or 34a.

A clip 148 is secured to each rear corner post 26 and to each forwardcorner post 28. The slip 148 is sized to securely hold a tapered pin 150which is disposed therein when not in use, as shown in dashed lines inFIGS. 7 and 8. A chain 152 is secured on one end thereof to theuppermost portion of the tapered pin 150 and the opposite end of thechain 152 is secured to the clip 148. The chain 152 is thus provided toprevent the pin 150 from being lost or misplaced when not in use. Thetapered pin 150 is sized to engagingly fit through the apertures 38 and40 of the respective transverse members 34 and 34a, and through theapertures 144 and 146 of each bar 140, during the operation of theoutrigger jacks 130, as will be described hereinafter.

It is apparent from the foregoing that when the tapered pin 150 isremoved from the apertures 38, 40, 144 and 146, each bar 140 will rotateand slide axially with the bore 36 of each transverse member 34 and 34arespectively. Therefore each outrigger jack 130 may be rotated andpushed inward-1y to a nonoperating position, as shown in FIGS. 1 and 4,in which the outrigger jacks 130 will not interfere with subsequentoperations. Each outrigger jack 130 is supported in this nonoperatingposition by a bracket 154, which is secured to each respective post 30.

OPERATION Let it be assumed, for the purposes of describing theoperation of the portable collapsible scaffold of the invention, thatthe scaffold structure 12 is mounted on the bed of the pickup truck 10in the manner depicted in FIG. 2. It will be noted that the transversedimensions of the base structure 22 of the scaffold permit it to easilyfit between the side walls 16 of the bed of the truck, and thehorizontally extending runners 24 allow it to rest flatly and evenly onthe bed of the pickup truck 10. In this position, the base structure 2-2is secured to the bed of the pickup truck 10 in a manner such that thebase structure 22 of the scaffold can be quickly detached entirely fromthe bed of the pickup truck, and the scaffold can be off-loaded from thetruck in a manner hereinafter described.

With the scaffold secured on the truck, the truck can be driven to alocation :where work is to be performed on an elevated structure, suchas a telephone line, light pole, traffic light, or the like. During suchtransport of the scaffold to the location of the work to be performed,the booms 44 and 46 are pivoted downwardly to the substantiallyhorizontal, nested position which they are shown as occupying in FIG. 2of the drawings. In this position, the boom 46 is located inside theboom 44 and the work platform 54 extends substantially horizontally andin parallelism with the booms 44 and 46. In this position, a positiveinterlock of the booms and work platform exists such that an upwardforce applied to the inner boom 46 would not alone be sufiicient tocause the two booms to be pivoted about their respective horizontalpivotal axes. Rather, the result would be a greater binding action tending to prevent further upward movement of the booms, since to break awayfrom the existing interlock, the outer and uppermost boom 44 must bemoved upwardly slightly before the parallelogram-type, expanding motioncan be smoothly developed.

To the end of permitting the positive interlock to be disengaged, andthe booms to pivot upwardly to the position depicted in FIG. 1, thehydraulic piston and cylinder assemblies 114 and 116 are provided. Bothof these assemblies are actuated simultaneously by hydraulic power fluiddelivered from the pump 112. As the piston rod 120 of the main pistonand cylinder assembly 114 is extended, the short piston rod 128 of theauxiliary piston and cylinder assembly 116 is simultaneously extended sothat both of the booms 44 and 46 are simultaneously pivoted upwardlyabout their horizontal axes.

Once the interlock is disengaged by the upward movement of the upper andouter boom 44, the function of the auxiliary piston and cylinderassembly 116 is completed, and the remainder of the upward movement ofthe booms 44 and 46 can be completed by the use of the main piston andcylinder assembly 114. Accordingly, extension of the piston rod 120 fromthe cylinder 118 continues until the maximum elevation of the workplatform is attained. At this time, the fluid power provided to thecylinder assemblies 114 and 116 is shut off and the booms 44 and 46 arelocked in their upraised positions. The vehicle has, of course, beensteered so as to position the work platform 5 4 in the immediatevicinity of the structure which is to be repaired, or the location wherework is to be performed by the workman.

The workman next ascends a ladder, which is provided on the upper sideof the boom 44, using the foot supports 42 to gain access to thisladder. When the top of the ladder is reached, the workman can pivot theside guard fences 70 and 72 and the respective gate members 82 and 84 totheir raised positions and interlock them by means of the latchingsleeves 96, in a position as shown in FIGS. 1, 5 and 6. It should benoted at this point that, in some instances, it may be desirable for theworkman to open the side guard fences 70 and 72, and the respective gatemembers 82 and 84 to their operative positions prior to the elevation ofthe work platform 64 by upward pivotation of the booms 44 and 46. Thiscan be easily accomplished, and the workman can stand upon the workplatform 54 during the elevation thereof if this should be desired. Whenused in this manner, the workman can control the elevating and loweringof the work platform 54 by using the remote control unit 129, which issecured to the work platform 54. It is therefore apparent, that theentire operation can be performed by a single workman. Using the remotecontrol unit 129, the workman can also vary the height of the workplatform 54 to accommodate his position with respect to the particularapparatus being repaired.

Upon completion of the repairs or other operations carried out by aworkman standing on the work platform 54 while it is in its elevatedposition, the work platform 54 can be lowered to the position depictedin FIG. 2, by pivoting the boom 44 and 46 about their horizontal pivotalaxes and using a metering valve to bleed hydraulic power fluid slowlyout of the pistons. As the power fluid is dispelled from the cylinders,the piston rods 120 and 128 will move into the respective cylinders 118and 126 under the weight of the booms 44 and 46 and the work platform54. Thus the booms 44 and 46 avill gradually be lowered to theircollapsed and nested status.

In this position, the side guard fences 70 and 72, and the respectivegate members 82 and 84 will be pivoted to their inoperative status asdepicted in FIGS. 2, 3, and 4. Each latching sleeve 96 is pivotedgenerally upwardly, thereby releasing the engagement between therespective gate members 82 and 84. Each gate member 84 is then pivotedin a direction 92, as shown in FIG. 5, to a position generally adjacenteach respective side guard fence 70 and 72. Each gate member 82 is thenpivoted in a direction 90 to a position generally adjacent therespective gate member 84. It is apparent, that due to the relative sizeand positioning of the gate members 82 and 84 with respect to each sideguard fences 70 and 72, as described hereinbefore, each gate member 82and 84 will lie in a position substantially parallel to each respectiveside guard fence 70 and 72 after each gate member 82 and 84 has beenpivoted in the direction 90 and 92 respectively to a position asdescribed hereinabove.

It should be noted that prior to pivotingly closing each gate member 84of the latching sleeve 96 is pivoted downwardly to a position, whereinthe latching sleeve 96 generally engages one side portion of therectangular portion 86 of each gate member 84. The latching sleeve 96 isretained in this position by the flange portion 80 of each sideguardfence 70 and 72, respectively, when the gate member 84 is pivoted into aclosed or inoperative position.

After the gate members 82 and 84 have been pivoted to the closed orinoperative position, the side guard fences 70 and 72 are pivoted in adirection 78, as shown in FIG. 6, to a position generally adjacent thebase frame 68 of the work platform 54.

The interconnection between each hinge member 74 and each lug 76,respectively, is such that the gap, which results when each side guardfence 70 and 72 is pivoted to a position substantially parallel to thebase frame 68, is slightly greater than combined widths of the two gatemembers 82 and 84, positioned adjacent each side guard fence 70 and 72,respectively. Therefore, when each side guard fence 70 and 72 is pivotedin the direction 78, to a position parallel to the base frame 68, eachgate member 82 will lie generally adjacent the base frame 68, and eachsideguard fence 70 and 72, and each gate member 82 and 84 will liesubstantially parallel to the base frame 68. The particular overlappingof each side guard fence 70 and 72 and each of the respective gatemembers 82 and 84, and the offset of the interconnection between eachhinge member 74 and each respective lug 76, interacts and cooperates tosubstantially hold the work platform 54 in the closed or inoperativestatus, as described hereinabove.

It is apparent that the side guard fences 70 and 72 and the respectivegate members 82 and 84 may be pivoted to an assembled or operativeposition, as shown in FIGS. 1, and 6, from the closed or inoperativeposition, as shown in FIGS. 2, 3 and 4, by reversing the described folddown procedure.

In many instances, it is desirable to clear the bed of the pickup truck10 for other uses, such as hauling various sizes and weights of goodsand commodities from one location to another. For this to beaccomplished, it is, of course, necessary to remove the portablecollapsible scaffold 12 from the pickup truck 10. This may be veryquickly and easily accomplished by a single person who may, of course,be the driver of the truck.

To accomplish this, a person need merely lift each outrigger jack fromengagement with the respective bracket 154. The bar of each outriggerjack 130 is then slid generally outwardly within the bore 36 of eachtransverse member 34 and 34a, respectively, to a position wherein eachoutrigger jack 130 will suificiently clear the sides 16 of the pickuptruck 10. In this position the bar 140 is rotated within the bore 36 ofeach transverse member 34 and 34a, to rotate each jack 130 to a positionwherein each threaded sleeve 136 of each outrigger jack 130 extendsgenerally perpendic-ular to the projected axis of each respectivetransverse member 34 and 34a.

The bar 140 of each outrigger jack 130 is then adjustingly rotated andslid within each bore 36 of each respective transverse member 34 and34a, to a position wherein the apertures 38 and 40 of each transversemember 34 and 34a are aligned with the apertures 144 and 146 of eachrespective bar 140. Each tapered pin is then removed from the clip 148and inserted through the aligned apertures 38, 144, 146 and 40, therebysecuring each bar 140 in position with respect to each transverse member34 and 34a, respectively. Since the tapers of the apertures 38, 144, 146and 40 are sized to matingly fit the taper of the tapered pin 150, asthe pin 150 is moved in a generally downwardly direction through theapertures 38, 144, 146 and 40, the engagement of the pin 150 in saidapertures will become increasingly tighter. Further, since the taperedpin 150 is initially inserted through the aperture 38, which is locatedabove the horizontal centerline of the respective transverse member 34and 34a, the general disposition of the pin 150 in the apertures 38,144, 146 and 40 (as shown in FIG. 8) is such that any movement at thetapered pin 150 will be in a generally downwardly direction, therebygenerally increasing the tightness of the fit therebetween.

It is apparent from the foregoing, that any movement of the bar 140 ofthe outrigger jack 130 within the above 36 of the respective transversemember 34 or 3411 will result in the tapered pin 140 moving in agenerally downward direction and, thus increasing the tightness of thefit of the tapered pin 150 as described hereinbefore. Therefore duringthe operation of each outrigger jack 130, secure engagement of eachoutrigger jack 130 with the base structure 22 is virtually assured,thereby providing a safe interconnection between each outrigger jack 130and the base structure 22.

It is apparent from the foregoing, that in the operating position of theoutrigger jacks 130, as shown in FIGS. 2 and 3, there are four outriggerjacks 130 located at the four corners of the base structure 22 of thescaffold 12. The operator may then pass from jack to jack and by turningeach of the handles 138 on the several jacks in equal relatively smallincremental amounts a number of consecutive times, the portablecollapsible scaffold 12 can be lifted from the bed of the pickup truck10. If the tailgate of the pickup truck 10 is then lowered, the pickuptruck 10 may simply be driven out from under the runners 24 of the basestructure 22 of the scaffold 12, to leave the scaffold 12 supported inthe air by the four outrigger jacks 130. Occasionally it may bedesirable to use the scaffold 12 while it is thus supported on theoutrigger jacks 130, and this may be successfully accomplished due tothe sufficiency of the counterbalancing weight afforded by the basestructure 22.

It should also here be noted that by slight modification of thestructure of the jacks 130 from that which is illustrated in thedrawings, the entire scaffold 12 may be completely lowered to the groundby consecutively turning the handles 138 of each outrigger jack 130 soas to shorten the outrigger jacks 130 until the runners 24 rest upon theground. The outrigger jacks 130, and more particularly each bar 140 ofeach outrigger jack 130 may then be removed from engagement with eachrespective transverse member 34 and 34a, by first removing the taperedpin 150 and then sliding each bar 140 in a generally outwardly directionalong the bore 36 of each respective transverse member 34 and 34a untileach bar 140 is completely removed therefrom.

In this position of the scaffold structure 12, as shown in FIG. 4, itwill be noted that the self-contained power plant, which includes theengine 108, the hydraulic pump 112 and the piston and cylinderassemblies 114 and 116, is still present in its same location on thebase structure 22, and can be utilized while the scaffold 12 is restedon the ground for elevating the booms 44 and 46. Thus, the scaffold 12can still be employed in the location at which it is rested upon theground for moving the work platform 54 to a relatively high verticallevel to permit access to be gained to structures upon which repairs areto be effected.

Loading of the scaffold 12 on the vehicle and securement on the bedthereof is achieved in precisely the reverse manner to that in which thescaffold 12 is offloaded from the vehicle as hereinbefore described. Asingle person may accomplish such loading without difficulty.

Although a preferred embodiment of the portable collapsible scaffold ofthe invention has been described in order to permit its construction andoperation to be clearly understood by those having ordinary skill in theart, it is to be understood that various changes and modifications maybe made to the depicted structure without departure from the basicprinciples upon which the invention is based. All changes andmodifications of this type are therefore deemed to be circumscribed bythe spirit and scope of the invention.

What is claimed is:

1. A portable, collapsible scaffold structure for mounting on a selfpowered vehicle comprising:

a base structure adapted to be detachably secured to the bed of the selfpowered vehicle, having a forward end portion and a rear end portion;

a plurality of transverse members extending generally horizontallyacross said base structure and secured to said base structure;

outrigger jacks detachably engaging said transverse members, eachoutrigger jack including:

an elongated sleeve, having an upper end portion and a lower endportion;

a ground contacting portion adjustably engaging a lower end portion ofthe elongated sleeve, whereby the height of the elongated sleeve isadjustable by raising and lowering the ground contacting portion;

a bar having an end portion secured to the upper end portion of theelongated sleeve and having the opposite end thereof slidingly engagingone of said transverse members;

means detachably securing each bar in position with respect to eachtransverse member;

a pair of elongated boom elements, each pivotally secured at one end tothe base structure; and

a horizontally extending work platform comprising:

a generally rectangularly shaped base frame pivotally secured to theends of said booms opposite their ends pivotally secured to said basestructure;

a pair of side guard fences extending generally perpendicular to thebase frame, in one position thereof, and each side guard fence pivotallysecured to one side of said base frame in such a manner that when eachside guard fence is pivoted to a position generally parallel to saidbase frame, a gap exists between each side guard fence and said baseframe;

a pair of gate members pivotally secured to opposite ends of each sideguard fence, one of the gate members in each pair being pivotable to aposition generally adjacent and parallel the respective side guardfence, and the other of said gate members in each pair being pivotableto a position generally adjacent the opposite gate member and such that,in this position, the respective pair of gate members generally occupythe gap between the respective side guard fence to which they aresecured and the base frame when each side guard fence is pivoted to aposition generally parallel to said base frame; and

means for elevating and lowering the booms by pivotation about saidhorizontal axes.

2. A scaffold structure as defined in claim 1 wherein said boom elementsare substantially parallel and are secured to said base structure athorizontally spaced locations from each other for pivotation aboutspaced, substantially parallel, horizontal axes.

3. A scaffold structure as defined in claim 1, wherein said boomelements are substantially parallel, and are secured at one end to therear portion of the base structure, said boom elements being secured tosaid base strucmm at horizontally spaced locations for pivotation aboutspaced, substantially parallel horizontal axes, one of said boomelements having its horizontal pivotal axis forward of the horizontalpivotal axis of the other boom element and being of a lesser transversedimension than said other boom element, and said boom elements beingdimensioned to nest in a horizontally extending position ofsubstantially coplanar alignment.

4. A scaffold structure as defined in claim 2, wherein the work platformforms a parallelogram with said booms and base structure when said boomsare pivoted upwardly.

5. A scaffold structure as defined in claim 3, wherein the work platformforms a parallelogram with said booms and base structure when said boomsare pivoted upwardly, and wherein said work platform occupies a positionin substantially coplanar alignment with said nested booms.

6. Scaffold structure as defined in claim 1, wherein the means toprovide power for elevating and lowering the booms includes:

extensible piston and cylinder means connected between said basestructure and at least one of the booms to provide power for elevatingand lowering both booms simultaneously about said horizontal axes; and

means for supplying power fluid to said piston and cylinder meansmounted on said base structure.

7, The scaffold structure of claim 1, wherein each of said bars istubular and has a pair of apertures, oppositely disposed and insubstantial alignment; and wherein each transversemember is tubular andincludes a pair of apertures oppositely disposed and in substantialalignment, such that in one position of each bar in the bore of eachtransverse member, the apertures in each bar are substantially alignedwith the apertures in each respective transverse member, and; furtherwherein the means to secure each bar in position with respect to eachrespective transverse member includes a pin disposed through saidapertures in each respective transverse member and through said alignedapertures in each respective bar.

8. The scaffold structure of claim 1, wherein each side guard fence ofthe work platform includes, a flange portion on one side thereofextending generally perpendicular to said side guard fence, one of saidgate members being pivotally secured to each of said flange portions,said flange portion sized such that when one of said gate members ispivoted to the position generally adjacent and parallel to each sideguard fence, the opposite gate member can then be pivoted to a positiongenerally adjacent and parallel the other said gate member.

9. The scaffold structure of claim 8, wherein the horizontal length ofeach of said gate members is slightly less than the horizontal length ofeach side guard fence respectively, such that when one gate member ispivoted to a position parallel to the respective side guard fence, saidgate member will not interfere with the other of said gate members.

10. The scaffold structure of claim 9, wherein the combined horizontalwidth of the pair of gate members is slightly less than the gap betweeneach side guard fence and the base frame, such that when each side guardfence is pivoted to a position substantially parallel to the basestructure, each of said gate members will be substantially parallel tosaid base frame and one of said gate members of each side guard fencewill be adjacent the base frame.

11. A portable, collapsible scaffold structure for mounting on a selfpowered vehicle comprising:

a base structure having a forward end portion and a rear end portion;

a plurality of transverse members extending generally horizontallyacross said base structure and secured to said base structure, eachtransverse member having a bore therein;

outrigger jacks detachably engaging said transverse members, eachoutrigger jack including:

an elongated sleeve having an upper end portion and a lower end portion;

a ground contacting portion adjustably engaging a lower end portion ofthe elongated sleeves whereby the height of the elongated sleeve isadjustable by raising and lowering the ground contacting portion;

a bar, having a bore extending a distance therethrough, secured on oneend portion thereof to the uppermost end portion of the elongated sleeveand having the opposite end thereof slidingly disposed in the bore ofeach transverse member;

means to secure each bar in position with respect to each transversemember;

boom means having an end pivotally secured to the base structure;

a horizontally extending work platform pivotally secured to said boommeans at an end opposite its end pivotally secured to said basestructure; and

means for elevating and lowering said boom means by pivotation aboutsaid horizontal axis.

12. The scaffold structure of claim 11, wherein each bar includes a pairof apertures, oppositely disposed and in substantial alignment; andwherein each transverse member includes a pair of apertures oppositelydisposed and in substantial alignment such that in one position of eachbar in the bore of each transverse member, the apertures in each bar aresubstantially aligned with the apertures in each respective transversemember; and further wherein the means to secure each bar in positionwith respect to each respective transverse member, includes a pindisposed through said apertures in each respective transverse member andthrough said apertures in each respective bar.

13. The scaffold structure of claim 12 wherein one of the apertures ineach transverse member is disposed above the horizontal centerline ofsaid transverse member so that when the pin is disposed first throughsaid aperture so disposed above said horizontal centerline and thenthrough the remaining apertures in each respective transverse member andthrough the apertures in each respective bar, the pin will be disposedin a generally downward direction.

14. The scaffold structure of claim 13 wherein the apertures in each barand the apertures in each respective transverse member are provided tomatingly fit the shape of the pin being inserted therethrough.

15. The scaffold structure of claim 14 wherein the shape of the pin istapered so that any movement of the bar or the transverse member willresult in the pin more tightly engaging said apertures.

16. The scaffold structure of claim 11 wherein there are four outriggerjacks, two of said jacks being disposed on the opposite sides forwardend portion, and two of said jacks being disposed on the opposite sidesof the rear end portion respectively, of said base structure.

17. A portable, collapsible scaffold structure for mounting on a selfpowered vehicle comprising:

a base structure having a forward end portion and a rear end portion;

elongated boom means pivotally secured at one end to the base structure;

a horizontally extending work platform comprising:

a generally rectangularly shaped base frame pivotally secured to the endof said boom means opposite its end pivotally secured to said basestructure;

a pair of side guard fences extending generally perpendicular to thebase frame, in one position thereof, and each side guard fence pivotallysecured to one side of said base frame in such a manner that when eachside guard fence is pivoted to a position generally parallel to saidbase frame, a gap exists between each side guard fence and said baseframe;

a pair of gate members pivotally secured to opposite ends of one of saidside guard fence, each gate member being sized such that one of saidgate members in each pair can be pivoted to a position generallyadjacent and parallel to the respective side guard fence to which it issecured, and the other of said gate members in each pair of gate memberscan be pivoted to a position generally adjacent the opposite gatemember, and such that, in this position, the pair of gate membersgenerally occupy the gap between the guard fence to which they arepivotally secured and the base frame when each side guard fence ispivoted to a position generally parallel to said base frame;

means for elevating and lowering said boom means by pivotation on saidbase structure; and

means connected to said base structure for elevating said base structureWith respect to the ground to permit said self powered vehicle to bedetached and driven from under said portable collapsible scaffoldstructure.

References Cited UNITED STATES PATENTS REINALDO P. MACHADO, PrimaryExaminer US. Cl. X.R.

